Speedriven BOVs: 3 Holes v. 6 Holes


Speedriven formally introduced the world to their billet aluminum diverter valves (commonly called “blow-off valves“, or BOVs) a few short weeks ago, but the first versions of these clever parts were first put on cars in late 2013, and have undergone over a year of high-octane, real-world testing. The parts have proven their durability- but what is it, exactly, that makes them so clever?

For starters, the factory BOVs used by Mercedes-Benz and AMG on their twin-turbocharged V12 cars are made of plastic. It’s a high-quality plastic, of course- but as the first generation of twin-turbo V12 cars starts to get on in years the plastic is starting to show signs of age, especially around the bolt-holes. Speedriven’s BOVs are machined from aircraft-grade aluminum, which is significantly more durable.

On the factory units, the stem is molded into the plastic “cap” of the diverter valve. This stem can crack and break during service (as shown in the photo, above), and a failure at that point means the entire BOV would need to be replaced. On Speedriven’s BOVs, the stem is, itself, made of high-strength metal, and is threaded into the cap such that- if the stem ever did break- it could be easily replaced without the need to replace the entire BOV assembly.

Finally, the factory BOV from Mercedes features 3 bolt-holes, which perform the dual tasks of holding the two main parts of the BOV together against the force of the mechanism’s internal spring and bolting the assembly to the car. This arrangement means that, in order to install the BOV, the technician has to awkwardly press the BOV parts against the turbo while, at the same time, keeping the bolt-holes aligned with the corresponding threaded holes in the turbo, inserting the bolt, and, finally, screwing in the bolts. That’s a lot to do with only two hands!


The billet Speedriven BOV design has 6 holes instead of 3, which allows the technician to properly place the seals and springs inside the BOV while the assembly is on his bench. Once assembled, the Speedriven BOV is now infinitely easier to install onto a waiting turbocharger, allowing for installation in under 2 hours.

The Speedriven BOV sounds a lot better, too. 😉

You can see some of the design drawings for Speedriven’s billet aluminum BOVs, below. Once you know what you’re looking at, you can see that it’s clearly a better mousetrap component than the factory Mercedes unit- and, let’s face it: you deserve smarter parts.

Speedriven BOV Design Drawings